PubMed Health⌕ Search

Biomedical subjects

J Boffa

Publications and source records attributed to J Boffa.

At least 19 recordsLinked to original sources
PubMed2003

[An exceptional etiology of left ventricular aneurysm: type AA amyloidosis].

Left ventricular aneurysms most often occur in the course of myocardial infarction. In rare cases they can be detected when the coronary network is devoid of any lesions. The aetiology is therefore multiple and dependent on the context. One aetiology seems less exceptional and concerns idiopathic aneurysms encountered in the African population, where the role of a "debilitating condition" such as tuberculosis has been evoked. We report the case history of a young patient from Zaire with a left ventricular aneurysm discovered in association with ganglionic tuberculosis complicated by AA amyloidosis. Histological analysis allowed the aetiological diagnosis to be established. Aneurysmal dilatation of the left ventricle was reported in the presence of amyloid deposits at the intra-myocardial arteriole level, whereas the context suggested a tubercular role. In spite of the difficulty of establishing a precise aetiological diagnosis, there seems to exist a consensus for surgical management.

Adult↗
PubMed1994

Sex, alcohol and violence: a community collaborative action against striptease shows.

Between September 1988 and February 1989, Anyinginyi Congress, an Aboriginal community-controlled health organisation, facilitated a collaborative community action against striptease shows in public bars in Tennant Creek. This action resulted in changes to the guidelines of the Northern Territory Liquor Act to regulate striptease shows in public bars and began other processes of addressing alcohol related problems in the community. The composition and strategies of both the pro- and anti-striptease lobbies are analysed within the context of changing power relationships between Aboriginal and non-Aboriginal people, as epitomised in the growth and consolidation of Aboriginal community-controlled organisations in Tennant Creek. The role of the media in shaping the course and direction of the debates as well as the response of the Northern Territory government as the final arbiter in the striptease conflict are scrutinised. The use of sex to sell alcohol is a legitimate public health concern and community action for healthier public policy is an important strategy in creating supporting environments for health.

Alcohol Drinking↗
PubMed1994

Beta-2 microglobulin as a marker for HIV infection.

Beta-2 microglobulin is a sensitive surrogate test for HIV infection for use in jurisdictions where HIV antibody tests are not allowed to be performed on life insurance applicants by law/regulation. The advantage of beta-2 microglobulin over T cell testing, which is a surrogate test also used by the life insurance industry for detecting HIV infection, is the stability of B 2M in serum over long periods of time.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Statistical analysis of HIV seropositive results from 1988-1993 performed on life insurance applicants.

This review of statistical data, derived from HIV antibody testing performed on life insurance applicants over a period of five and one-half years, reflects the evolving nature of the HIV epidemic in the United States and demonstrates how the findings in the life insurance low risk population mirror the trends and changes that are occurring in the general population.

Actuarial Analysis↗
PubMed1991

Longitudinal evaluation of condylar position in extraction and nonextraction treatment.

In 111 patients pretreatment and posttreatment condylar position was evaluated with corrected tomograms taken with the mandible in centric occlusion. Seventy-nine of the patients were treated by nonextraction procedures and 32 were treated by extraction procedures, 27 of the patients with the extraction of one or more premolars and 5 with the extraction of one or more anterior teeth. When the condylar positions before and after treatment were compared in the entire sample of 111 patients, in the nonextraction patients, in the extraction patients, and in extraction patients relative to nonextraction patients, no statistically significant differences were found. Thus condylar position was stable during treatment and did not behave differently under extraction and nonextraction conditions. On an individual basis, condylar retropositioning, as defined in this study, occurred in only nine of the 222 joints examined and was noted in patients treated both with and without extraction.

Adult↗
PubMed1991

Condylar position and maxillary first premolar extraction.

Condylar position in 17 patients whose Class II treatment (14 with edgewise appliances and 3 with Begg appliances) included extraction of the maxillary first premolars and in 17 control patients was compared by means of corrected tomography. The condyles in both groups were in an anterior position, and there were no statistical differences between the groups. In addition, no statistical correlation was found when the posttreatment bite depth, interincisal angle, and maxillary incisor inclination were correlated with condylar position. Thus, as determined in this study, condylar position was unrelated to treatment, bite depth, interincisal angle, and maxillary incisor inclination.

Adolescent↗
PubMed1989

Condylar position and Class II deep-bite, no-overjet malocclusions.

By means of corrected tomography, the positions of the condyles in 19 click-free persons with Class II malocclusions characterized by a bite depth greater than 50%, no overjet, and an interincisal angle of greater than 140 degrees were compared with a positions of the condyles in 21 control subjects. Average condylar position in both groups was concentric and no significant differences between groups were found. In addition, no significant correlation was noted when condylar position was related to bite depth.

Adolescent↗
PubMed1986

The frequency of bitewing radiographs.

A model for use in analyzing the implications of different rates of caries incidence and progression for the timing of bitewing radiographs was developed. Estimates of progression rates and incidence patterns were derived from an analysis of serial bitewing radiographs. A time schedule for taking the next radiographs was determined so that carious lesions would be detected before radiolucencies reach the inner half of the dentin. For asymptomatic persons with extensive exposure to fluorides and no unrestored enamel lesions on the last radiographs, bitewing films could be scheduled every 2.5 to 3 years. For persons with little exposure to fluorides or with many early enamel lesions or at least one deep enamel lesion that has not been restored, radiographs should be performed every 6 months to 1 year.

Adolescent↗
PubMed1986

The expected benefits from alternative frequencies of bitewing radiograms.

From an analysis of serial bitewing radiograms, we have developed a mathematical model of the initiation and progression of approximal carious lesions in the permanent teeth. The model is used to estimate the expected number of lesions, per individual, not detected until they reach the inner half of the dentin, as a function of the frequency with which radiograms are taken between the ages of 8 and 20 years. If radiograms are performed every 6 months and lesions not restored until radiolucencies appear in the dentin, under 5% of all lesions developing over the 12-year period will reach the inner half of the dentin before detection. If radiograms are taken every 2 years, about 18% of all lesions will have reached the inner half of the dentin before detection. The sensitivity of these conclusions to different assumptions is examined.

Adolescent↗
PubMed1984

A longitudinal analysis from bite-wing radiographs of the rate of progression of approximal carious lesions through human dental enamel.

Four to ten years of serial bite-wing radiographs from over 700 children from five groups, three in Sweden and two in the U.S., were interpreted. By analysing changes in the depth of unfilled lesions over time, the mean time and probability distribution for the time a lesion remains in both the outer half and inner half of the enamel were estimated. The procedure incorporated information on filled lesions and non-progressing lesions and thus minimized bias that results in overestimation of the progression rate. In primary teeth, in both the U.S. and Swedish groups, it took on average 12 months for a lesion to progress through the outer half of the enamel and on average 10-12 months for a lesion to progress through the inner half. In newly-erupted first permanent molars, it took 21-23 months for a lesion to progress through the outer half of the enamel and between 19 (U.S. data) and 28 months (Swedish data) for progression through the inner half. In older adolescents in the two Swedish groups, progression was slower: 38-41 months through the outer-half and 47-56 months through the inner-half. In older U.S. adolescents, progression appeared to be more rapid: 16 months through the outer half of the enamel and 27 months through the inner half. The duration of time a lesion remains in different halves of the enamel could be approximated by a piecewise exponential or exponential probability distribution, which exhibits extreme variability. Assuming duration in each half of the enamel follows an exponential distribution with a mean of 2 yr, about 10 per cent of new lesions will progress through the enamel in one year and 25 per cent in two years. However, over 40 per cent of the lesions will not have progressed in 4 yr. There were no consistent differences in the rate of progression by sex, between upper and lower dentitions, for premolars versus molars, or between high and low-risk individuals.

Adolescent↗
PubMed1984

Use of the Kaplan-Meier estimate to reduce biases in estimating the rate of caries progression.

An important determinant of how often to perform dental radiography is how rapidly dental caries progress. Estimates of the rate of progression of dental caries have been biased by the elimination of filled lesions and non-progressing lesions (i.e. censored data) from the analysis. We illustrate the use of the Kaplan-Meier estimate to incorporate information from these cases and demonstrate the effect of using this information on estimates of the rate of progression of approximal caries.

Adolescent↗
PubMed1984

Study design to reduce biases in estimating the percentage of carious lesions that do not progress within a time period.

Much of the available information on the rate of caries progression comes from studies in which two examinations have been done and the percentage of lesions that do not progress from a carious state between the examinations recorded. Extrapolation from this type of study is subject to two offsetting biases. On the one hand, slow progressing lesions that have been in a state for a long time before the first examination may progress between examinations. When these are counted as lesions that progress within the time period between the two examinations, there will be an underestimation of non-progressing lesions. On the other hand, slow progressing lesions will be over-represented in the sample of lesions detected at the first examination. This will result in an overestimation of non-progressing lesions. We suggest a three examination protocol to minimize these biases.

Dental Caries↗
PubMed1984

Reliability of coding depth of approximal carious lesions from non-independent interpretation of serial bitewing radiographs.

In order to help understand the effectiveness of preventive care and the source of variation in treatment decisions, it is important to determine intra- and interexaminer agreement on the presence and depth of radiolucencies on bitewing radiographs when serial radiographs on individuals are available for interpretation. Serial radiographs on 24 subjects were read in succession, and one of four depth codes was assigned to approximal lesions. The radiographs were then read a second time, both by the person who had initially read the radiographs and by a second reader. Intraexaminer agreement on presence of a lesion ranged from 60% to 90%; four of the five readers had an agreement of over 78%. Interexaminer agreement on presence of a lesion ranged from 71% to 84%. Intraexaminer agreement on depth of lesion ranged from 64% to 80%; four readers had an agreement of over 73%. Interexaminer agreement on depth of lesion ranged from 59% to 76%.

Adolescent↗